Does hair really get thicker and darker when you shave it?

We don’t know who started the myth that hair grows back thicker after you shave it, but mothers have been using it for far too long to keep their daughters from shaving their legs too soon. When scientists test this, they find that shaving or any other way of getting rid of hair has no effect on how fast hair grows back.

So why does the idea keep going around? The most obvious answer has to do with the shape of our hair. These protein filaments made of keratin that stick out all over the body have tapered ends. When you shave, the ends of your hair become blunt and rough, but as the hair grows out, they become finer again.

This is why stubble from two days ago feels scratchier than a beard from two weeks ago, and why you might think shaving makes hair thicker.

“Women always shave their legs. If the hair grew back thicker or darker, they would look like gorillas “Dina Fine Maron at Scientific American talks to dermatologist Amy McMichael. “Also, we’d never have to worry about losing hair on our heads if cutting the hair shaft would make it grow back thicker.”

But don’t just believe what a dermatologist says. In 2007, two doctors busted a few medical myths in The British Medical Journal. One of the myths they busted was about hair growing back.

“A clinical trial in 1928 showed that shaving didn’t affect hair growth,” they wrote. “Newer studies show that shaving does not change how thick or fast hair grows back. Also, shaving only takes off the dead part of the hair, not the living part that is under the skin, so it is unlikely to change how fast or what kind of hair grows back.”

Only puberty seems to be an exception to this rule. When boys start shaving for the first time, their hair may start to grow back thicker over time. This has nothing to do with shaving, though. Instead, the changes in hormones during puberty affect hair thickness and other things.

Now, you may have also heard something different. In the name of fashion, people who sell tubs of hot, painful wax will often say that waxing makes hair grow back less and thinner. But as physician Michael Vagg writes on The Conversation, that’s just a trick of the eye: “Plucking and waxing remove the hair from the follicle at the base. This means that the hair will grow back a little slower and have a tapered end instead of a blunt one.”

After putting waxed and shaved hair myths to the test on Catalyst, science reporter Paul Willis says, “There is evidence that repeated waxing may eventually damage the follicle enough to stop it from making hair, but that would take years.”

“Like many of your body’s functions, the way your hair looks and acts will show your overall health and where you came from,” writes Michael Vagg. “You can’t make it grow faster or thicker unless you have a skin problem or a problem with how the hair cycle works.”

So shave, pluck, and wax as much as you want—the hair doesn’t care.